1. In a large pot, on medium-low heat, melt butter with oil. Sauté celery, onions and garlic until soft, about 10 minutes. Add white wine and reduce by half. Add rest of ingredients (except seafood, basil and parsley). Let simmer for about 20 minutes.
2. Add the crab, clams, shrimp and halibut and simmer covered for another 5 minutes. Add the mussels, cover the pot and simmer until mussels open. Turn off heat and stir in parsley and basil.
3. Serve in bowls with Italian bread or grilled sourdough.